Fuel injection system with hydraulic circuit for internal combustion engine receives high-pressure fuel from common rail which passes to injection valve and spaces over pistons

摘要

The fuel injection system (1) incorporates a high- pressure feed line (5) and a high-pressure injection line (6) receiving fuel from the common rail fuel supply (3). A valve actuator (31) presses on a rod (61) which holds a first piston (36) forming part of a hydraulic coupling (35). High-pressure fuel may flow to a first chamber (80) over the first piston. The fuel flows from a chamber under the piston through a connecting channel (84) to a second chamber (83) under a second piston (37). This presses on a rod (63) which may open a control valve (41) with a ball (51). This may control leakage (55) from a control chamber (43) over the injection valve needle (11).